Conventionally, when an electronic part that generates large heat caused by a supplied large current is mounted on a printed wiring board, a heat radiation member is embedded in the printed wiring board at a position where the electronic part is mounted so as to radiate the heat generated from the electronic part by using this heat radiation member (for example, Japanese Laid-open Patent Publication No. 05-304223).
However, when the heat is radiated to the outside of the printed wiring board by using the aforementioned embedded heat radiation member, a heat radiating sheet and the like are needed to be additionally provided on or above the back surface of the printed wiring board. Moreover, in order to supply the large current to the electronic part from the outside, a bus bar that is a terminal for the large current is also needed to be additionally provided on the printed wiring board. In other words, in the conventional technology, the number of members to be additionally provided on the printed wiring board becomes large to increase the member cost and the member mounting processes. This leads to increasing the manufacturing costs of the printed wiring board and a product into which this printed wiring board is built.